The invention relates to wireless devices, and more particularly, to a wireless optical input device that allows a user to interact with a computer.
There are a number of computer input devices that employ an electromechanical arrangement for effecting cursor movement and scrolling. In such an arrangement, the mechanical movement of a roller ball is converted into electrical signals. The electrical signals are then encoded into information that a computer can use, such as cursor X-Y position data or scrolling direction and distance. Mice and trackballs are the most common input devices that employ this type of electromechanical arrangement. In general, however, there are numerous applications for an electromechanical arrangement in computer input devices.
One problem associated with this type of electromechanical arrangement is that the actuating assembly (e.g., roller ball and the corresponding rollers) is prone to malfunction because of debris and or mechanical breakdown. Moreover, input devices such as mice require that the roller ball be in contact with a special surface (e.g., mouse pad) in order to function properly. This special surface is equally prone to debris and wear and tear, and tends to limit the area upon which the input device can move. For example, at times, a user may have to stop rolling the mouse, pick it up, and place it back down on the mouse pad so that the user can keep moving the mouse in the same direction in order to get the cursor to a desired position.
In response to solving these problems, optical assemblies have begun to replace the electromechanical assemblies. Unlike its electromechanical counterpart, an optical assembly does not have a roller ball and the corresponding rollers. As such, an input device employing an optical sensor assembly for performing functions such as cursor movement and scrolling is not prone to debris or mechanical wear, and can be used on most surfaces. Generally, an optical sensor assembly employs an optical sensor and a light emitting diode (LED). As the input device is moved, light from the LED reflects off a surface and is received by the optical sensor thereby forming a series of images. Distance and direction of cursor or scroll bar movement can then be determined from the images. In short, optical input devices provide an elegant solution to problems associated with electromechanical input devices.
However, it appears that there is currently no computer input device that employs such optical sensing technology in the context of a wireless input device. Wireless technology allows input devices such as mice and keyboards to be untethered from the host computer thereby providing the user with a greater degree of mobility and reducing desktop clutter. Thus, there is a need for an input device that offers the benefits of a wireless connection as well as the benefits associated with an optical sensor for effecting cursor movement, such as a wireless optical mouse.
Problems associated with such a wireless optical input device stem from competing factors underlying the two technologies. For instance, on one hand, optical assemblies require a significant amount of power (e.g., for powering the LED and optical sensor). On the other hand, wireless input devices are not tethered to an external power source. Thus, one must be provided internally to such a wireless input device. This basically limits the power source to a battery included in the wireless input device. To complicate matters, both practical and economic reasons dictate that the battery size cannot exceed certain physical constraints thereby limiting the life of the battery. As such, power intensive technology can prematurely deplete a battery included in a wireless input device. Hence, an effective power management scheme should be available to such a device.
There is a need, therefore, for a wireless input device that employs optical sensing to effect the likes of cursor movement and scrolling. Such a wireless input device should optionally employ power management techniques that allow the battery to avoid premature depletion. In a more general sense, there is a need-for power management techniques in wireless devices that employ power intensive technology.
One embodiment of the present invention provides a wireless input device that employs optical sensing to effect the likes of cursor movement and scrolling. The wireless input device can optionally employ power management techniques that allow the wireless input device""s power source to avoid premature depletion. Another embodiment of the present invention provides a wireless device having a power management algorithm controlling its power consumption. Another embodiment of the present invention provides a method for managing the power consumption of a wireless device.
The features and advantages described in the specification are not all inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and not to limit the scope of the inventive subject matter.